Manufacture of azodyestuffs for dyeing cellulose esters



reams a so, 1929.

-Iran STATES PATENT OFFICE.

osxaa masons, or BINNINGEN, NEAR BASEL, SWITZERLAND, ASSIGNOR TO THE Erma, orrnmoar. wonns normality sannoz, or BASEL, SWITZERLAND.

MANUFACTURE OF AZODYESTUI FS FOB DYEING CELL'ULOSE ESTERS.

No Drawing. Original application filed December 23, 1925, Serial No. 77,380, and in Germany January 6,

1925.,. Divided and this application filed March 16', 1927. Serial No. 175,929.

This application is a division of application Ser. No. 77,380,,filed December 23, 1925.

Dyestuffs suitable for dyeing cellulose esters, which are too diflicultly soluble for practical application, have been employed, up to now, either in the form of their bisulphite compound as stated in the specifications of British Patent No. 204,280 (1923) or as N-alkyl-o-sulphonic acids, according to the specifications of British Patents No.197,809 (1923), No. 200,873 (1923) and No. 212,029 (1924). During the dyeing process the acid groups of these dyestuffs are split off by bydrolysis, under the influence of the elevated temperature of the dyebath and the colors thus formed are then absorbed by the cellulose ester fibres.

It has now been found that it is possible to transform insoluble or difiicultly soluble azodyestuffs, containing neither sulphonic nor carboxylic groups and possessing a particular affinity for cellulose esters, into stable and soluble derivatives by introducing a radical of glycerine into the molecule of the dyestuffs in place of one or more hydrogen atoms of the aromatic nucleus. This can be performed by coupling diazoaryl-glycerine ethers, which possess neither sulphonic nor carboxylic groups, but which may possess any other substituents, with azo components containing neither carboxylic nor sulphonic groups.

The dyestuffs thus obtained, apart from their good solubility, are distinguished by a particular afiinity for cellulose esters, so that by their aid, bright and uniform shades may be obtained, without having to employ temperatures, which would be injurious to the fibres. In those cases, where the dyestuffs contain diazotizable aminogroups, the direct shades may be diazotized on the fibreand cou- I pled with suitable developers.

The dyestuffs obtained by the process as described above are entirely different from those referred to in the above mentioned patents; the dyeing with these last mentioned dyestuffs is only possible by the fact, that their acid groups, to which their solubility in water is due, are split off by hydrolysis during the dyeing process. In contradistinction to this, the glycerine radicals of the new dyestuffs are not split off during the dyeing process, so that uniform shades are obtained,

owing to the good penetration of the colors.

The following examples illustrate the improved process.

Ewample 1.

deposit which becomes soon gelatinous.

After some time, a solution of caustic soda is carefully added, until Congopaper shows only a weak reaction, whereby the coupling is finished and the dyestuff becomes crystalline. After filtering and drying the latter appears as abrown violet powder and its hydrochloride is much easier soluble in water than the corresponding dyestuff obtained'from nitroanisidine:

OCH :NH :NO,=1:2:4 and p-Xylidine.

For dyeing purposes, the solution of the hydrochloride is diluted with the necessary quantity of water, further additions being superfluous. In this bat-h, acetate silk is dyed in very uniform, golden yellow shades, and the dye bath is completely exhausted. The direct shade is transformed by diazotizing and developing with ,B-naphthol into a brilliantbluish red tone.

The dyestufl possesses most probably the I following formula l NO:

The dycstuff as developed on the fibre with B-llilPlithOl shows most probably the following formula.

on on oon.. ':n. ':n.

Ewamplc Q.

The dyestutf obtained according to Example 1 is filtered, stirred up with water and hydrocl-iloric acid and diazotized with (5,9 kg. of sodium nitrite at 0 (3. The diazocompound of the mon-oazodyestuii is then run into :a solution of 12,5 ot' metatoluyleno diamine in 100 kg. of water and rendered alkaline with caustic soda. Coupling takes place at once, a black gelatinous mass being precipitated; this is diluted with a great amount of water, aeidulated with acetic acid and then boiled up, whereby the gelatine is transformed into an easily tilterable mass. The dried disazodyestull forms a greenish black powder and its hydrochloride is easily soluble in water. Acetate sill; is d yed in deep brownish red shades.

The dyestufi' possesses most probably the following formula 1! one-n oemduqdnz Ema n iple 22 kg. of oaminoplienoxypropandiolhydrochloride (Bull. Soc. Chim. de France 13, 525 Chem. Centralblatt II, 356) are dis solved in 100 litres of water and 12 kg. of concentratet'l hydrochloric acid and then. diazotizcd with (3,9 kg. of sodium nitrite. An aqueous solutionot 23 kg. of l-aminoQ-naphtholethyletherhydrochloride in 400 litres of water is run into the clear and colorless solution of thedi azocompoand and the acid neutralized wit-hsodiuin acetate. Coupling takes place at once, a deep violet solution being formed, whereupon by the addition of about 10% of volume of common salt, the dyestuif can be precipitated to a. greenish glossy somewhat resinous deposit. After having been stirred for some time, the mass becomes completely solid and can easily be filtered. The dyestutf, which is obtained after drying, is a dark red brown powder and dissolves very easily in hot water in the form of its hydrochloride. It dyes acetate silk in copper colored shades. By diazotizing and developing with ,B-n aphthol, this shade changes into .a reddish dark blue.

The dyestufi' possesses most following formula:

on on O.CH2.CII. CH2 OCzHi The dyestufli as developed on the fibre with B-naphthol possesses most lowing formula Example .4.

probably the erat-ure of 75 C. U ou saltin out. the

violet solution yields the dyestutl' as a green 'ish .gi'oldcu resin, which alter cooling is tiltered and dried and forms a black powder of a bluish tone. Acetate sill: is dyed in orange shades: by diazotizi ng and developinn with [j-naphthol a deep, brownish Violet obtained.

The dyestutt' possesses most probably the following formula:

on on OEHLCIEHIBEH 7 NH: mw

The dyestufi" as developed on the fibre with B-naphthol possesses most lowing formula:

on on -(I)..CH2.( lHiC Ha probably the folprobably the fol- 75 What I claim is -1. A process for the preparation of amdyestuffs, containing neither'carboxylio nor .sulphonic groups, suitable for dyeing cellulose esters, consisting in coupling a diazocompound having at least one hydrogen atom of its aromatic nucleus substituted by a radical of glycerine, with an azo component.

2. As new products of manufacture, the herein described azod estuffs for dyeing cellulose esters, obtained in coupling a. diazotized aminoarylglycerineether free from car boxylic and sulphonic groups with on n20- component also free from carboxylic and sulphonic groups, said dyestuffs bein in the form of the hydrochloride easil so uble in water and when so dissolved dyeing cellulose esters of yellow to orange, red, brown, blue and violet tints, which when diazotized and developed are orange, red, brown, blue, violet and black.

In witness whereof I have hereunto signed my name this 3rd day of March, 1927.

a OSKAR KNECHT. 

